1. Field of the Invention
The present invention relates to the field of remote control of apparatus, and has for its object a hydraulic remote control device of an apparatus, particularly a high pressure cleaner.
2. Description of the Prior Art
At present, there are three principal remote control systems for high pressure cleaners, namely control by mechanical gun, control by wires and radio control.
Control by a high pressure mechanical gun is the most widespread system. The control is in this case controlled by hydraulic components and requires precise mechanical regulation as well as very good sealing of the hydraulic circuit, no protection against small leakage of water being provided.
A malfunction of the hydraulic system can give rise to discontinuities in the operation of the cleaner and, under certain conditions, give rise to incidents having serious consequences for the user and the cleaner.
Finally, this system permits only control of the starting and stopping of the cleaner and accordingly has the drawback of not permitting remote control of the different functions of the cleaner, such as selection of cold water only, hot water only or again hot water with a washing product. Stated another way, to change the mode of operation of the cleaner, it is necessary to revert to the machine.
Electric remote control by wire is another remote control mode for a cleaner. Remote control of the operations is ensured by a special high pressure hose, so-called twinned, which is to say having an electrical sheath with several conductive wires, associated with a high pressure conduit. As a result, the arrangement of this flexible conduit makes it burdensome. It is also fragile and difficult to manipulate because of its weight and its rigidity.
On the other hand, the remote control gun has the same drawbacks as the flexible sheath, namely susceptibility to shocks, limited maneuverability and high cost.
Finally, the cleaner is entirely stopped upon breakdown of one of the elements of the system and no longer satifies among other things the existing safety standards.
The third and last remote control measure existing for high pressure cleaners is remote control by radio frequency signals. This control principle permits remote control of the different operations of the cleaner through a conventional high pressure hose. Thus, the control is effected thanks to coded radio frequency emission, transmitted by means of the woven metallic sheath of the flexible hose. As soon as the user pulls the trigger, the emission becomes continuous and its radiation may adversely affect the environment of the flexible hose. The emission and reception may be disturbed in turn, and as a result bring about random stoppages of the cleaner, independently of the will of the user. In certain cases, the remote control will be impossible, for example when the environment of the cleaner is too disturbed. Moreover, the frequency of usage permits no faulty contact at the connection between the gun and the cleaner. As a result, it is necessary to safeguard the flexible hose from external moisture so as to protect against corrosion and prevent all contact between it and a metallic body risking interruption of transmission. This control system is difficult and requires moreover for its operation electric batteries which must be regularly recharged. Furthermore, it also has the drawback of preventing utilization of the cleaner in case of disturbance of emission and/or of reception and of being limited by the range of radio frequency emission.
Finally, remote control by electric wires and by radio frequency signals has also the drawback of not being able completely to shut off flow, particularly when the cleaner is stopped while using hot water or vapor phase.